Wrist rest assemblies are known for use along the front edge of a device to be operated by a person's hands or fingers, such as in front of a computer key board, computer mouse or other input device. It has been suggested that the use of such wrist rest assemblies can restrict damage to wrists from prolonged use of such devices. Heretofore, however, many known wrist rest assemblies have been formed with layers of cushioning material that do not provide the quality of support for the wrists that may be desired.
U.S. patent application No. 08/253,510 filed Jun. 3, 1994, and assigned to the assignee of this application discloses a wrist rest assembly for use along the front edge of a device to be operated by a person's hands or fingers, such as in front of a computer key board, computer mouse or other input device, which wrist rest assembly provides a layer of cushioning material that can provide better support for the wrists than has heretofore been provided, and further affords a degree of movement of the supported wrist relative to the surface on which the wrist rest is supported that has not been provided by known prior art wrist rest assemblies. That wrist rest assembly comprises (1) a base assembly having an upper pad support surface, which base assembly has a bottom or supported surface adapted to be supported on a horizontal surface along the front edge of the device; and (2) a pad comprising a layer of gel. A bottom surface of the elongate pad is supported on the upper pad support surface of the base assembly, and the pad has a sufficient width between its edges and thickness between its top and bottom surfaces (e.g., a thickness in the range of about 1/8 inch to 5 inches and a width in the range of about 1/2 to 10 inches with the larger widths providing both wrist and fore arm support) to afford supporting a users wrists on the top surface to help keep the wrists in a neutral position with a portion of the layer of gel beneath and conforming to the supported wrists to distribute the weight of the wrists over a wide area and affording significant motion of the top surface of the pad with the supported wrists relative to the bottom surface in a plane generally parallel to the upper surface of the base assembly.
Preferably the gel is a stable elastomeric block polymer gel similar to the gel described in U.S. Pat. No. 3,676,387, (the content whereof is hereby incorporated herein by reference) and preferably is the gel described in Example No. 3 of British Patent No. GB 1,268,431 (the content whereof is hereby incorporated herein by reference) except that the ratio of oil to block copolymer is in the range of 4 to 1 to 10 to 1 rather than being 5 to 1 as is described in that Example No. 3. That gel is quite similar to the gel in the pad commercially available from Minnesota Mining and Manufacturing Company, St. Paul, Minn., under the trade designation "Reston (T.M.) Flotation Pad", which pad for many years has been used in beds, wheel chairs and the like to prevent pressure points. The base assembly described in that application included a top portion having the upper pad support surface supporting the bottom surface of the elongate pad; a bottom portion having the bottom supported surface adapted to be supported on a horizontal surface; and means for supporting the top portion on the bottom portion with the elongate pad at a predetermined one of several different distances above the supported surface; that means being provided by the top portion of the base assembly comprising longitudinally extending rails projecting outwardly in opposite directions generally parallel to its upper pad support surface, and the bottom portion including generally parallel spaced vertically upwardly projecting support portions having opposed surfaces defining sets of grooves parallel to the supported surface and vertically spaced along the support portions, each of which sets of grooves is adapted to receive the rails to support the top portion with the top surface of the elongate pad at a different distance above the supported surface depending on which set of grooves the rails are engaged in.